Shred potatoes into a large bowl filled with cold water. Let the potatoes sit for 10 minutes to remove excess starches that come out while shredded. Drain and rinse potatoes until the water runs clean. Drain well. Lay out several paper towels onto a clean surface. Pour drained potatoes onto the paper towels and pat dry to remove excess moisture. Sprinkle with salt and pepper.

In a large non-stick skillet, heat oil until shimmering over medium-high heat. Pour the potatoes into the bottom of the non-stick pan and press potatoes into the bottom of the pan forming a skillet sized potato pancake. Let the hashbrowns simmer until they turn crispy and golden brown. Using two oven mitts and a large plate, very carefully invert the hashbrown onto the plate. Place skillet back onto the burner and slide uncooked side of the hashbrown into the skillet to cook on the other side until crispy and golden brown.

Remove from the burner and slide hashbrown into a pie pan.

In a large mixing bowl, whisk together eggs, garlic, cream, milk, flour, baking powder and salt. Stir in diced ham and cheese until evenly distributed.Pour into the prepared hashbrown crust. Place in oven and bake until the center is set - about 45 minutes for a standard pie plate. Check after 35 minutes to ensure it does not over cook.